Computing devices often communicate with each other by routing data through one or more network elements. For example, a first computing device (e.g., a mobile phone) may route data (e.g., real-time transport protocol (“RTP”) data) intended for a second computing device (e.g., another mobile phone) through a network-based transcoder, which may transcode the data into a format supported by the second mobile device. In some instances (e.g., in cases where the second computing device is not available), the data transmitted by the first computing device may terminate at a network element (e.g., a voicemail server).
In either scenario, a firewall may be used to prevent unauthorized data from reaching a network element. For example, a firewall may be used to prevent attack traffic (e.g., data intended to interrupt, corrupt, or otherwise interfere with one or more operations of the network element) from reaching the network element.
To facilitate some types of communication (e.g., RTP communication) between a computing device and a network element, a firewall may have to leave an entire range of ports associated with a network element (e.g., an entire user datagram protocol (“UDP”) port range associated with the network element) open. Unfortunately, this may allow malware residing on the computing device to spam or otherwise attack the network device by transmitting attack traffic to the network device by way of one or more of the open ports.